渗灌的非饱和土壤水二维流动的探讨

本文对渗灌条件下的非饱和土壤水二维流动问题进行了探讨。对水平二维流及垂直二维流均进行了重复实验,并建立了相应的非饱和土壤水二维流的数学模型。按有限差分的计算方法求到数学解且与实验结果相符合,验证了该数学模型的可行性。同时应用数学模型对田间渗灌在不同条件下(如不同初始含水量、不同的土质、不同的密实度及不同直径供水管等几个主要因素)的非饱和土壤水二维流进行了模拟计算。根据计算结果分别就上述各影响因素对田间渗灌的非饱和二维流动的差异性进行了分析,由此对田间渗灌中若干问题提出初步看法。

STUDY ON TWO-DIMENSIONAL FLOW OF WATER IN UNSATURATED SOIL UNDER SUBSURFACE IRRIGATION

The horizontal two-dimensional flow and vertical two-dimensional flow were tested in the laboratory and their mathematical models were developed respectively. The recults obtained from numerical calculation F with the finite difference method well agreed with those obtained from experiment. This shows that the mathematical models are applibable.The two-dimensional unsaturated flow in the soil under subsurface irrigation was simulated with the model under different conditions such as various initial water content in soil, varipus kinds of soil, different com.paction and water supply pipes with difterent diameters. On the basis of the data from calculation, the influences of various factors on two-dimensional unsaturated flow of the soil under subsurface irrigation are analyzed and some views about reasonable management of subsurface irrigation are recommended.